U.S. Cellular will roll out an LTE (Long-Term Evolution) mobile wireless network, reaching more than 25 percent of its subscribers by the holiday season late this year.

The deployment plan, announced Friday, represents a major acceleration of its plans compared with the timing indicated by an executive's statement last year. Steven Campbell, the company's chief financial officer, said last November that U.S. Cellular would test LTE this year and begin a commercial rollout in 2012, according to news reports. A launch in time for the U.S. holiday season would mean the network would be available by the end of November. U.S. Cellular has about 6.1 million subscribers.

LTE is designed to deliver several megabits per second both upstream and downstream, though the speed that individual subscribers enjoy is based on a variety of factors. Verizon Wireless has said its LTE network delivers between 5M bps (bits per second) and 12M bps, about 10 times the average speed of EV-DO (Evolution-Data Optimized), the 3G technology that both Verizon and U.S. Cellular use. U.S. Cellular did not estimate how fast its LTE network will be.

As a second-tier mobile operator, U.S. Cellular is focused on some markets that may receive less attention from the four major U.S. carriers. Its first phase of deployment will bring LTE to 24 market areas, including Milwaukee, Madison and Racine, Wisconsin; Des Moines, Cedar Rapids and Davenport, Iowa; Portland and Bangor, Maine; and Greenville, North Carolina. None of these cities was part of Verizon's initial rollout, though that carrier has said it will rapidly expand its LTE coverage this year to include about 140 more cities.

U.S. Cellular said it will introduce a portfolio of LTE devices during the first phase of the network rollout and expand those offerings throughout 2012.